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Unit 5 & 6: Evolution

Your Inner Fish Video Questions

1. Fish were the first creatures with what trait?

2. When did the first mammals show up?

3. Sir Richard Owen was the first scientist to notice what skeletal pattern?

4. Instead of limbs fish have what?

5. Where did the paleontologists go for their first expedition?

6. In the early stages of development, all animals begin as what?

7. If you look at a fish and human embryo side by side, how similar do they look?

8. What does Molly possess that most humans do not?

9. What is Sonic Hedgehog responsible for?

10. How many fingers do people in the Hubbard family have?

11. What does the name Tiktaalik mean?

12. Who was the first to predict that an animal like Tiktaalik would exist?

13. What features does Tiktaalik have that fish typically do not?

14. What type of exercise could Tiktaalik do that other fish cannot?

15. What is the piece of anatomy that changed the world?

Analysis Questions

If a person wanted their child to have 6 fingers on each hand, explain how you think a doctor would be

able to accomplish this.

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Explore Your Inner Animals http://www.pbslearningmedia.org/resource/1eacb154-b9fd-4775-8918-c913306048aa/explore-your-inner-animals-

your-inner-fish/

Click on the human skeleton, the arrows to rotate the skeleton, and the links to videos to

find the answers to these questions Legs: How are human legs shaped to help us balance and walk efficiently?

______________________________________________________________________________

Hands: What are tetrapods? ________________________________________________________

Ears: How did the bones of our inner ear form? _________________________________________

Brain: Large areas of a primate’s brain are used for _______________________________________

Back: How does the shape of our back keep us balanced to walk on 2 legs? ______________________

______________________________________________________________________________

______________________________________________________________________________

Teeth: Teeth show an evolutionary history with what other parts of our anatomy? ________________

______________________________________________________________________________

______________________________________________________________________________

Eyes: How can we find out about an organism’s eyes if they don’t fossilize? _____________________

______________________________________________________________________________

______________________________________________________________________________

Eyes: How did the placement of our eyes change over time? Why? ___________________________

______________________________________________________________________________

______________________________________________________________________________

Evolution 101

http://evolution.berkeley.edu/evolibrary/article/0_0_0/evo_02

What is biological evolution?

_______________________________________________________________________

What is the central idea of evolution?

_______________________________________________________________________

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Mechanisms of Evolution

Descent with Modification

http://evolution.berkeley.edu/evolibrary/article/evo_15

Evolution only occurs when ___________________________________________________

_______________________________________________________________________

Which of these 2 scenarios is an example of evolution? Explain your choice.

A. Beetles on a diet OR B. Beetles of a different color

_______________________________________________________________________

_______________________________________________________________________

Mechanisms of Change

http://evolution.berkeley.edu/evolibrary/article/evo_16

What are the 4 processes for evolutionary change? Explain each in your own words.

1. __________________________________________________________________

__________________________________________________________________

2. __________________________________________________________________

__________________________________________________________________

3. __________________________________________________________________

__________________________________________________________________

4. __________________________________________________________________

__________________________________________________________________

Genetic Variation

http://evolution.berkeley.edu/evolibrary/article/evo_17

What are the sources of genetic variation? Briefly explain each in your own words.

1. __________________________________________________________________

__________________________________________________________________

2. __________________________________________________________________

__________________________________________________________________

3. __________________________________________________________________

__________________________________________________________________

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Genetic Drift

Driftworms

Evolution (change over time) is how modern organisms have descended from ancient ancestors over long

periods of time. It is responsible for the remarkable similarities we see across all life and the amazing

diversity of that life. Evolution is often described as "descent with modification." (passing changes

down to offspring) Evolution only occurs when there is a change in gene frequency (how often a gene

occurs) within a population over time. These resulting genetic differences can be passed on to the next

generation over time (i.e., inherited), which is what really matters in evolution - long term change.

The major forces of evolution are mutations (changes or errors in DNA), gene flow (immigration and

emigration), non-random mating (using criteria to select a mate), natural selection (survival of the

fittest) & genetic drift (the disappearance of an allele from a population).

These forces cause changes in genotypes (the genetic code) & phenotypes (the physical appearance)

over time and also determine the amount & kind of variation seen in a population.

Genetic drift is the RANDOM decrease in gene frequency within a population due to the role of "chance"

and/or unpredictable "accidents." Small populations that are isolated from one another can differ

greatly as a result of genetic drift. The cheetah is a great example.

Driftworms have only one gene that controls skin color. These worms reproduce asexually and are

connected to their parents by lines. In any population of driftworms, each worm gives rise to exactly

one worm in the next generation. It doesn't matter how good your driftworm genes are if you get

squished by a shoe before producing offspring!

How can alleles disappear?

An ant may get stepped on

A rabbit may get swept up by a tornado

An elephant may drink a parasitic protozoan living in a puddle

A plane may crash killing a Nobel Prize winner

Procedure:

1. On the Driftworm Worksheet, color each of the five worms in Generation 0 (zero) a different color.

You may choose the colors. Number the worms 1-5 (top to bottom).

2. Roll the die and put a dot (.) next to the corresponding worm. If you roll a 6, roll again.

3. Repeat Step 2 five times. This is the population size of the worms

4. Starting at the bottom, draw a line from each dot to the bottom-most worm in the next generation.

5. Color the worm(s) in the next generation the same color as its/their parent.

6. Repeat Steps 2-5 until ALL the worms in a generation are the SAME color. This is when that gene’s

allele is “fixed”. Please be patient since it may take a while. Group data will vary accordingly.

7. Answer the questions on the page after your driftworm worksheet.

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Which gene (allele) became “fixed” in your gene pool? _______________________________

Why is there no point in adding more generations after an allele (gene) has become fixed?

_______________________________________________________________________

Using your group's data, what was the number of generations until an allele became fixed?

_______________________________________________________________________

Which genes “drifted” from your gene pool? ______________________________________

If the color of your driftworm was determined by the color of the environment it lived in, would

the disappearance of all the other colors still be considered “genetic drift”? Why or Why not?

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

Lizards in an Evolutionary Tree Video

What made the lizards in the video different species? What type of speciation caused this to

happen? ________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

Speciation

http://evolution.berkeley.edu/evolibrary/article/evo_40

What is a species? ________________________________________________________

_______________________________________________________________________

What is speciation? ________________________________________________________

_______________________________________________________________________

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How can speciation occur?

1. Geographic isolation (http://evolution.berkeley.edu/evolibrary/article/evo_43) -

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

2. Reproductive isolation (http://evolution.berkeley.edu/evolibrary/article/evo_44) -

__________________________________________________________________

__________________________________________________________________

__________________________________________________________________

Natural Selection

Woolyboogers

Background: You and your team are crewmembers on

the Beagle in 1831. Darwin has asked your team to assist

him in collecting data on a strange and unusual bird that

he has discovered on the Galapagos Islands. He has

called this bird the woolybooger. Darwin and your team

search the islands and find three different populations

of this creature. During your observations of these

three populations, you discover that each group is similar

in appearance except for mouth variations. Some

woolyboogers have a knife-shaped mouth, some have a

clip-shaped mouth, and some have a tweezer-shaped mouth. All of the birds have migrated to an island

that only has dried beans for them too eat and the hours of daylight needed for finding food is steadily

decreasing due to the change in seasons.

Darwin and your team study the woolybooger’s life on the Galapagos Islands. During your last few

months on the islands, you discover a new rare woolybooger, which has a spoon-shaped mouth. On the

Beagle, Darwin and your team discuss which beak type of woolybooger will survive the best on the island

and how the population of woolyboogers will change over time or evolve.

Procedure:

1. You will run through five trials of feeding by the woolyboogers. You will be assigned a feeding

tool to gather your favorite food, beans. You must use your utensil as demonstrated to capture

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food. You cannot scoop the beans into the cup, which represents your stomach. You must lift the

beans, one or two at a time, with your utensil.

2. You will be required to capture at least 20 beans in a trial in order to survive. If 20 beans are

not captured, your woolybooger has died. When a woolybooger dies, in the next trial you will play

the role of the offspring of the most successful surviving woolybooger (the woolybooger

capturing the most beans).

3. The first trial will last 1 minute 15 seconds, the second 1 minute, the third 45 seconds, the fourth

30 seconds and the fifth will be 15 seconds. The teacher will time the class.

4. Because woolyboogers with spoon-shaped mouths are rare, only a few of you will be assigned this

tool for the first generation of woolyboogers.

Hypothesis: Which beak do you think will work best? How do you think the Woolybooger population will

change over time (evolve)?

______________________________________________________________________________________

______________________________________________________________________________________

DATA TABLE:

Number of Woolyboogers at beginning of each trial

Mouth

shape

1 minute 15

seconds 1 minute 45 seconds

30

seconds 15 seconds

Final

Number

Knife

Clothespin

Tweezer

Spoon

Describe how the Woolybooger population evolved (changed over time)? How did this compare

to your hypothesis from before we ran this simulation? (at least 3 sentences) _____________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

Which variation of Woolybooger beak was best adapted to survive on the island? Why? ______

_______________________________________________________________________

_______________________________________________________________________

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What happened to the Woolyboogers who were less adapted to survive on the island? _______

_______________________________________________________________________

_______________________________________________________________________

What would be necessary in nature for all the variations of Woolyboogers to be able to coexist

and all reproduce without one beating out another? ________________________________

_______________________________________________________________________

_______________________________________________________________________

What is a real-life example of the Woolybooger, where one organism has a definite advantage

over another organism of the same species? Explain. _______________________________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

In what ways was this simulation realistic? _______________________________________

_______________________________________________________________________

_______________________________________________________________________

In what ways was this simulation unrealistic? _____________________________________

_______________________________________________________________________

_______________________________________________________________________

What do you think were the big ideas to be learned from this activity? __________________

_______________________________________________________________________

_______________________________________________________________________

The Beak of the Finch Video

Natural Selection at Work

http://peppermoths.weebly.com/

Here you will see one of the most famous examples of natural selection: The Peppered Moths.

Click on “The Life Cycle of the Peppered Moth”

Briefly describe what the Peppered Moth looks like: ________________________________

_______________________________________________________________________

_______________________________________________________________________

Who eats peppered moths? ________________________________________________

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What adaptation do moths have that help keep them from getting eaten? ________________

_______________________________________________________________________

_______________________________________________________________________

What do moths do to prevent death in the colder months? ___________________________

_______________________________________________________________________

_______________________________________________________________________

What colors can the peppered moth come in? _____________________________________

_______________________________________________________________________

Click on “Impact of Pollution”

What happened to the peppered moth population by 1900? ___________________________

_______________________________________________________________________

Why did people think the moths were all of a sudden becoming much darker? ______________

_______________________________________________________________________

_______________________________________________________________________

Why do you think there were more dark moths than before? __________________________

_______________________________________________________________________

Who first proposed “Natural Selection? _________________________________________

What is natural selection? ___________________________________________________

_______________________________________________________________________

_______________________________________________________________________

How are the peppered moths turning from light colored to dark colored and example of natural

selection? _______________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

Why has the number of dark moths decreased in the last 50 years? ____________________

_______________________________________________________________________

_______________________________________________________________________

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Click on “Bird’s Eye View” and read the instructions for the Peppered Moth Game

Do the light forest first and then you can go back and do the dark forest.

The number of dark and light moths was equal when the simulation started. How did the number

of dark and light moths compare at the end of the simulation? Why? ___________________

_______________________________________________________________________

_______________________________________________________________________

Go back and do the dark forest simulation.

What happened to the number of light and dark moths in this simulation? Why? ___________

_______________________________________________________________________

_______________________________________________________________________

Explain how the color of the moths increases or decreases their chances of survival. ________

_______________________________________________________________________

_______________________________________________________________________

Explain the concept of "natural selection" using your moths as an example. _______________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

What would happen if there were no predators in the forest? Would the colors of the moths

change over time? Defend your answer? ________________________________________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

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Jeff Corwin Video Questions

Circle the BEST answer

1. What do scientists say makes the Galapagos Islands unique?

a. The different kinds of plants living on the islands

b. The large numbers of species living on the islands

c. The different animal species living on the islands

d. The large numbers of marine iguanas on the islands

2. Which choice BEST explains why each island in the Galapagos has unique kinds of iguanas?

a. Iguanas prefer a marine environment

b. Some iguanas are better swimmers than others

c. The species arrived on the islands in different ways

d. The species adapted to each islands unique habitat

3. Sea lion bulls stake out the best territory on the water in order to attract other bulls.

a. True

b. False

4. Why do Galapagos sharks lie still on the ocean floor?

a. They are sleeping

b. They are being social

c. They are waiting for food

d. Scientists don’t know why

5. Penguins are an unusual species to find in the Galapagos Islands because

a. The islands are tropical and penguins live in very cold regions

b. The islands are very cold and the penguins live in tropical regions

c. The islands tropical water don’t have adequate food sources for the penguins

d. The islands arctic waters can easily cause the penguins to suffer from hypothermia

6. Why is the tortoise breeding program on Santa Cruz Island important?

a. The tortoise population has increased

b. No one knows how long a tortoise’s lifespan is

c. No one knows how 2 tortoise species became extinct

d. The tortoise population has decreased

7. Masked Boobies lay 2 eggs. Which of the following does NOT occur when the eggs hatch?

a. One egg hatches before the other

b. The parent raises both hatchlings

c. The parent ignores the second hatchling

d. The first hatchling pushes the second one put of the nest

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8. Marine iguanas on Espanola Island each show a different coloration of their scales in order to

a. Dig nests

b. Stand out in the sand

c. Identify their territory

d. Appear healthy for a mate

9. Why is the giant iguana a good example of Charles Darwin’s theory of adaptive radiation, or the

way a species adapts to its environment?

a. They help each other survive

b. They are larger than any other iguana species

c. They live on the largest island in the Galapagos

d. They live on the smallest island in the Galapagos

10. If Charles Darwin could return to the Galapagos Islands today, which of the following is an

example of a change he might see?

a. No changes

b. More islands

c. More tortoises

d. New species of iguanas

Analysis: Explain how Natural Selection is evident on the Galapagos Islands. Use at least 1 organism

from the video to support your answer. ________________________________________________

______________________________________________________________________________

__________________________________________________________________________________________________

“Survival of the Sneakiest”

http://evolution.berkeley.edu/evolibrary/article/0_0_0/sneakermales_01

Read the cartoon and answer the questions

When it comes to crickets, what does fitness mean? _______________________________

_______________________________________________________________________

Is calling good or bad for a cricket's fitness? _____________________________________

Give some examples of selection at work in this cricket story. _________________________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

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How does selection favor calling? ______________________________________________

_______________________________________________________________________

_______________________________________________________________________

How does selection favor not calling? ___________________________________________

_______________________________________________________________________

_______________________________________________________________________

Darwin

http://www.sciencechannel.com/games-and-interactives/charles-darwin-game/

On the bottom of the main image, click on “More about Darwin.”

What was the name of the ship that Darwin traveled on? _____________________________

Where in the world did Darwin make his most important discoveries? ____________________

_______________________________________________________________________

What was the name of Darwin’s most famous book? _________________________________

Click on “Natural Selection” on the top of the main image. Fill in the blanks.

Part 1: Every _____________________ exhibits _____________________.

Not all members within a ___________________ are exactly the _____________________.

What variations can individuals exhibit? _________________________________________

_______________________________________________________________________

Part 2: Many _________________ are passed from parents to their __________________.

Part 3: Life in the wild is _____________________ and organisms with the most beneficial

_____________________ will prosper (succeed and reproduce). This is known as

“_______________________________________.”

If an organism has traits that help it survive or attract mates, what will it be able to do?

_______________________________________________________________________

_______________________________________________________________________

Eventually, _____________________ traits can spread throughout a species.

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Survival Game: Who wants to live a million years?

You will now play this survival game to model evolution. This game is not easy so I would be sure

to look at the hints. Also, when the game starts be sure to pay attention to the environment,

the years that have gone by, and what hints Darwin gives you. Finally, there is one part of the

game called the “Life Preserver.” This is not accurate as far as evolution is concerned, but will

help you win the game. Note: It is difficult to win but not impossible.

Notice that there is initially a lot of variation in the population. What are some variations that

you see? ________________________________________________________________

_______________________________________________________________________

Choose your population.

The animals with _____________________ most suited to the new

_____________________ will _____________________.

After the first cycle (≈ 140,000 years), what has happened to the population of animals?

_______________________________________________________________________

_______________________________________________________________________

After the second cycle (≈400000 years), what has happened to the population of animals?

_______________________________________________________________________

_______________________________________________________________________

If your animals died (which they probably did), why did they die? ______________________

_______________________________________________________________________

Play the game again. How long could you keep your animals alive? _______________________

Why did some animals die, while others thrived? ___________________________________

_______________________________________________________________________

_______________________________________________________________________

Why did the physical characteristics (phenotypes) of the overall population change? ________

_______________________________________________________________________

_______________________________________________________________________

Now take the Natural Selection Quiz! What was your score? ________________

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Darwin Stations

Station I: England

Here we are going to look at some animals that Darwin typically saw around his home in England.

Look at the sheet labeled “DOGS.”

1) A species is a group of organisms that can breed to produce babies. Two elephants can reproduce

and have elephant offspring, but an elephant and a chicken cannot reproduce and have a baby

“chickephant.” Are all of these dogs the same species? _______________

2) List three differences between the dogs: 1. ____________________________________

2. ____________________________________

3. ____________________________________

3) I have a male and female of each of these dogs. I want to have a dog that is very small and black

and has long hair. Which two dogs should I breed? ____________________________________

4) Why do the dogs look so different from one another?

__________________________________________________________________________

_________________________________________________________________________

5) Look at the sheet labeled “PIGEONS.” Do you think that these pigeons are all the same species?

Why or why not? _____________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

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Station II: South America 1) What is the main difference between the ground sloth and the three-toed sloth? ___________

__________________________________________________________________________

__________________________________________________________________________

2) What is the main difference between the ancient capybara (Phoberomys) and the modern

capybara? __________________________________________________________________

__________________________________________________________________________

3) Darwin found the bones of the ground sloth and what he thought was an ancient capybara in

South America. He asked around, but nobody in South America had ever seen either of those

animals alive. What had happened to them? __________________________________________

__________________________________________________________________________

__________________________________________________________________________

4) List two reasons why that might that have happened.

1. _________________________________________________________________________

2. _________________________________________________________________________

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Station III: Galapagos Islands 1) When Darwin reached the Galapagos Islands, he saw many of the finches that are shown in the

picture. He noticed that they had different-shaped beaks. Why do the different finches have

different beak shapes? _________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

2) According to the diagram, what does the Warbler finch eat? ___________________________

3) These three finches eat seeds. Draw a line between each finch and the seed that it likes to eat.

4) All three of the birds from the previous question live on one island. The island becomes warmer

and the hickory trees (that produce hickory nuts) produce fewer nuts. Sunflowers like the heat and

more sunflowers grow and produce seeds. What will happen to the population sizes of the birds on

the island?

Bird A’s population will increase / decrease / stay the same (circle one).

Bird B’s population will increase / decrease / stay the same (circle one).

Bird C’s population will increase / decrease / stay the same (circle one).

Sunflower Seeds

Sesame Seeds

Hickory Nuts

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Station IV: Australia

Look at the paper with the skulls on it.

These are two skulls photographed from different angles. All those labeled “1” are from one animal,

and those labeled “2” are from another animal.

1) List three ways that skull #1 is similar to skull #2.

1.

2.

3.

2) Look at the picture labeled “A.” Count the number of teeth on each jaw.

The jaw of skull #1 has ______ teeth.

The jaw of skull #2 has ______ teeth.

3) List two more differences between the two animals’ skulls.

1.

2.

4) What do you think these animals eat?

5) Do you think these two animals are closely related to one another?

6) Skull #1 is from a marsupial wolf and skull #2 is from a gray wolf. Why do you think the skulls

look so similar even though the animals are not closely related to each other?

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Comparing Evolutionary Theories

The theory of evolution revolutionized the way we view the history of the human species and

other life on earth. Darwin was not the first one to propose the theory of evolution but his

description of the mechanism for it, natural selection, has proven to be more plausible and

therefore accepted by the scientific community today. Use the resources found here to help

you compare Darwin’s theory of natural selection with Larmarck’s proposed mechanism for

evolution

Lamarck believed that microscopic organisms appear spontaneously from inanimate materials

and then transmute, or evolve, gradually and progressively into more complex forms through a

constant striving for perfection. The ultimate product of this goal-oriented evolution was

thought by Lamarck to be humans. He believed that evolution was mostly due to the inheritance

of acquired characteristics as creatures adapted to their environments. That is, he believed

that evolution occurs when an organism uses a body part in such a way that it is altered during

its lifetime and this change is then inherited by its offspring. For example, Lamarck thought

that giraffes evolved their long necks by each generation stretching further to get leaves in

trees and that this change in body shape was then inherited. Likewise, he believed that wading

birds, such as herons and egrets, evolved their long legs by stretching them to remain dry.

Lamarck also believed that creatures could develop new organs or change the structure and

function of old ones as a result of their use or disuse.

Lamarck's incorrect idea of the cause of evolution

Jean-Baptiste Lamarck 1744-1829

If Lamarck was correct, the children of cowboys who have developed bowed legs as a result of a

lifetime of riding horses would be born with bowed legs as well. That, of course, does not

occur. Likewise, the children of professional weight lifters are not born with enlarged

muscles.

While Lamarck's explanation of evolution was incorrect, it is unfair to label him a bad scientist.

In fact, he was at the cutting edge of biological research for his time.

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How does Lamarck explain the diversity of organisms? _______________________________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

Explain Lamarck’s theory of use and disuse of organs. Do you agree or disagree with his

theory? Why? ____________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

Darwin came to understand that any population consists of individuals

that are all slightly different from one another. Those individuals

having a variation that gives them an advantage in staying alive long

enough to successfully reproduce are the ones that pass on their

traits more frequently to the next generation. Subsequently, their

traits become more common and the population evolves. Darwin

called this "descent with modification."

The Galápagos finches provide an excellent example of this process.

Among the birds that ended up in arid environments, the ones with

beaks better suited for eating cactus got more food. As a result,

they were in better condition to mate. Similarly, those with beak

shapes that were better suited to getting nectar from flowers or

eating hard seeds in other environments were at an advantage there.

In a very real sense, nature selected the best adapted varieties to

survive and to reproduce. This process has come to be known as natural selection.

Darwin did not believe that the environment was producing the variation within the finch

populations. He correctly thought that the variation already existed and that nature just

selected for the most suitable beak shape and against less useful ones. By the late

1860's, Darwin came to describe this process as the "survival of the fittest." This is very

different from Lamarck's incorrect idea that the environment altered the shape of individuals

and that these acquired changes were then inherited.

Nineteenth century critics of Darwin thought that he had misinterpreted the Galápagos finch

data. They said that God had created the 13 different species as they are and that no

evolution in beak shape has ever occurred. It was difficult to conclusively refute such counter

arguments at that time. However, extensive field research since the early 1970's has proven

Darwin to be correct.

Charles Darwin 1809-1882

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What led Darwin to formulate his idea about the origin of species? On what did he base his

explanation for his ideas about the origin of species? ______________________________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

What data does Darwin rely upon for his argument? ________________________________

_______________________________________________________________________

_______________________________________________________________________

EVOLUTION MECHANISMS: COMPARISON SAMPLES

Consider the long legs of wading birds such as herons and egrets, birds that are common around

rivers and marshes. How could such a bird evolve such long legs? Read the following scenarios

and discuss each with your partner. Use the questions at the bottom to help in this

discussion.

Assume that the species ancestral to these birds had short legs, and could only wade into very

shallow water along the shoreline, eating snails and small fish.

SCENARIO A.

A change in the environment increased competition between the birds, and resulted in depletion

of the food supply in the shallow waters. This created a need for the short-legged birds to

wade into deeper water in order to survive, which forced them to stretch their legs, because

they didn't want to get knocked over by the little waves. This stretching caused their legs to

get a little longer.

When these birds produced chicks, the baby birds grew up with the slightly longer legs

inherited from their parents. These offspring birds needed to wade out even further, so they

stretched their legs even more, and made them a little bit longer yet. And their chicks grew up

with even longer legs inherited from their parents. And so on...

Eventually, after many generations of this, the legs of these birds were so much longer than the

ancestral birds that the new birds could be described as a new species.

SCENARIO B.

Within the species of ancestral short-legged shore birds, there is a range of leg lengths, from a

little bit shorter to a little bit longer than the average leg length, and these leg lengths tended

to run in families (i.e., leg length was hereditary).

A change in the environment increased competition between the birds, depleting the food supply

in the shallow waters. The birds with slightly longer legs, of course, could wade out a little

farther. As a result, they got more food, lived a little longer, and therefore produced more

chicks. Those with the shorter legs would tend to starve to death. Since the tendency for leg

length was already inheritable, the surviving "long-leggers" tended to have more long-legged

chicks, which likewise tended to get more food and produce more chicks. And so on...

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Eventually, after many generations of this, the average leg length of these birds was so much

longer than in the ancestral birds (along with other connected changes) that the new birds could

be described as a new species.

Answer these questions based on the scenarios above.

Which theory (scenario A or B) sounds like an explanation that Lamarck might give? Explain your

answer.

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

Which theory (scenario A or B) sounds like an explanation that Darwin might give? Explain your

answer.

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

Go back to the two scenarios. Underline the specific terms and phrases that distinguish the

Lamarkian explanation from the Darwinian one.

Which explanation is most likely correct given the evidence for Darwin’s and Lamarck’s

theories? _______________________________________________________________

_________________________________________________________________________________________________

What term did Darwin use to explain how new species emerged? ______________________

_________________________________________________________________________________________________

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Create a brief summary of the main differences between the two theories. Use the following

table for your summary.

Lamarck Darwin

Conception of species:

Mechanism of new species

production:

Example of this type of

explanation:

Phenomena the model can

account for:

How the Earth Was Made Video

Directions: Answer the following questions during the movie. All of the questions go in

order with the movie.

1. How did the Earth form?

2. What was the source of the heat that keeps the interior of the Earth very hot?

3. How else is it used by scientists?

4. What is the current accepted age for the Earth?

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5. Where did most of the water on Earth come from?

6. What type of rock us found under the continents?

7. What did stromatolites add to the atmosphere? What happened to the iron in the

oceans when this compound was added?

8. How did Alfred Wegner explain the same fossils found in areas separated by many

miles of ocean?

9. What is the rate at which North America and Europe are moving apart? (give your

answer in cm and inches)

10. What 2 countries were found in the heart of the supercontinent Rodenia?

11. Describe what happened to the Earth 700 million years ago.

12. How did the development of the ozone layer allow life to develop on land?

13. What caused the greatest mass extinction 250 million years ago?

14. What caused the dinosaurs to go extinct 65 million years ago? List both events.

15. How are mountains such as the Alps formed?

16. Describe what happens to rocks between 2 colliding continental plates.

17. By what processes was the Grand Canyon formed?

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18. What evidence for the ice ages can be found in the granite of Central Park?

19. When could the next ice age occur?

20. Which planet will Earth resemble when the core finally cools and plate tectonics stops?

Evidence of Evolution

http://www.ucmp.berkeley.edu/education/explorations/tours/stories/middle/intro.html

Complete the chart as you move through the interactive.

Evidence What it tells us:

Past Lives

1. growth rings in fossil trees or shells Growth rings tell us the number of years that individual lived.

2. curled up fossil trilobites

3. the contents of fossil nests

4. fossils of many individuals of the same species together

5. a change in the shape of a feature over time

Geologic Time

1. layers in the rocks

2. index fossils

3. fossil shells on mountain tops

4. identical fossils on widely separated continents

Paleoecology

1. fossil marine animals in the desert

2. shapes of leaf edges

3. tooth marks in fossil shells

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4. fossil pollen

Biodiversity

1. fossils of organisms no longer alive today

2. features that are shared by more than one species

3. the extinction of many fossil species at the same time

4. the extinction of one group of organism, like corals, on which other organisms depend

Examining the Fossil Record Fossils are traces of organisms that lived in the past. When fossils are found, they are analyzed to determine the

age of the fossil. The absolute age of the fossil can be determined though radiometric dating and determining the

layer of rock in which the fossil was found. Older layers are found deeper within the earth than newer layers.

The age and morphologies (appearances) of fossils can be used to place fossils in sequences that often show

patterns of changes that have occurred over time. This relationship can be depicted in an evolutionary tree, also

known as a phylogenetic tree.

There are two major hypotheses on how evolution takes place: gradualism and punctuated equlibrium. Gradualism

suggests that organisms evolve through a process of slow and constant change. For instance, an organism that

shows a fossil record of gradually increased size in small steps, or an organism that shows a gradual loss of a

structure. Punctuated equilibrium suggests that species evolve very rapidly and then stay the same for a large

period of time. This rapid change is attributed to a mutation in a few essential genes. The sudden appearance of

new structures could be explained by punctuated equilibrium.

Speciation

The fossil record cannot accurately determine when one species becomes

another species. However, two hypotheses regarding speciation also exist.

Phyletic speciation suggests that abrupt mutations in a few regulatory genes

occur after a species has existed for a long period of time. This mutation

results in the entire species shifting to a new species. Phyletic speciation

would also relate to the Punctuated Equilibrium hypothesis regarding

evolution. Divergent speciation suggests that a gradual accumulation of small

genetic changes results in subpopulation of a species that eventually

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accumulate so many changes that the subpopulations become different

species. This hypothesis would coincide with the gradualism model of

evolution. Most evolutionary biologists accept that a combination of the two

models has affected the evolution of species over time.

Procedure:

1. The diagram you are creating requires a large space. To create your workspace, tape together __

sheets of standard sized paper. Use a ruler to draw the following chart on your workspace

Time Period

( __ inches wide)

Began (years ago)

( __ inches wide)

Fossils

( __ inches wide)

Wyomington (oldest) 995,000 (Each row here must be __ inches tall)

Ohioian 745, 000

Nevadian 545,000

Texian 445,000

Oregonian 395,000

Coloradian 320,000

Montanian 170,000

Californian 80,000

Idahoan (the present) 30,000

2. The group of "fossils" you will work with are fictitious animals. Each fossil on your sheet is marked

with a time period. Cut out each fossil and make sure you include the time period marked below it.

3. Arrange the fossils by age. On your data chart, place each fossil next to the period from which the

fossil came from. The term "upper" means more recent and should be placed lower in the row. The

term "lower" means an earlier time period, fossils from a "lower" time period should be place

toward the older time periods. In each fossil column, you may have 3 specimens, one from the main

time period, one from the upper and one from the lower. Not all fossils are represented, illustrating

the incompleteness of any fossil record.

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4. While keeping the fossils in the proper age order, arrange them by morphology

(appearance). To help you understand the morphology of the specimen, view the

diagram. Arrange the fossils using the following steps.

a. Center the oldest fossil at the top of the fossil column (toward the oldest

layer)

b. Through the chart, those fossils that appear to be the same (or close to the same) as the

fossils preceding them should be placed in a vertical line

c. During a certain period, the fossils will split into two branches. In other words, one fossil from

that period will show one type of change, and another fossil will show a different change. When

this happens, place the fossils side by side in the appropriate time period. From this point on you

will have two lineages.

5. Once all the fossils have been placed correctly according to time and morphology, tape or glue the

fossils in place.

Give a brief description of the evolutionary changes that occurred in the organism. _________

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

During which time period did the fossils differentiate into two branches. ________________

Explain how the chart illustrates both punctuated equilibrium and gradualism. Use specific

fossils from the chart to support your answer. ____________________________________

_______________________________________________________________________

_______________________________________________________________________

Examine the fossil that was unearthed in a museum, apparently the labels and other information

were lost. Using your fossil record, determine the time period this fossil is likely from.

_______________________

Of the two major species that arose from the parent species, which was more successful? How

do you know? _____________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

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Evidence of Evolution: Morphology

Much evidence has been found to indicate that living things have evolved or changed gradually during

their natural history. The study of fossils as well as work in embryology, biochemistry, and comparative

morphology provides evidence for evolution.

I. Fossils

Study the figure at right.

Which rock layer is the oldest? _____

Which rock layer is the youngest? _____

Explain what can scientists learn about evolution

when comparing different fossils in different rock

layers? (Use terms like relatedness, extinction,

transition etc.) You must write at least two

complete sentences.

________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

________________________________________________________________________________________

II. Homologous Structures

Carefully examine the drawings of the bones in Figure 1 on the next page. Look for

similarities among the various animals.

1. Color each bone of the human arm a different color. Color the Humerus blue, the

Radius red , the Ulna green, and the bone groups of the hand (metacarpals and

phalanges) should be yellow. Then color the corresponding bones (containing the

same pattern) in each of the other animals the same color as the human bone (i.e. the humerus blue in the human, it should be blue in all the other animals).

2. Describe at least two functions of each set of bones below:

Animal Functions

Human

Whale

Cat

Bat

Bird

Frog

Lizard

3. Are the bones arranged in a similar way in each animal? _________

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These structures are formed in similar ways during embryonic development and share like arrangements;

however, they have somewhat different forms and functions. They are called homologous structures.

4. What does the prefix “homo” mean? ______________

III. Analogous structures

Examine the butterfly wing and the bird wing shown in Figure 2.

1. What function do these structures share? _______________________________________

Phalanges

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2. How do the structures differ internally and externally? (give me three) ________________

_________________________________________________________________________

_________________________________________________________________________

_________________________________________________________________________

3. Do birds and insects share any structural similarities that would suggest they are closely

related in the single tree of life that includes all organisms? Explain. ____________________

_________________________________________________________________________

_________________________________________________________________________

_________________________________________________________________________

_________________________________________________________________________

Some apparently unrelated animals have organs with similar functions, yet are very different in

structure and form. These structures are called analogous structures.

V. Vestigial structures

Gradual changes have occurred through time that have, in some cases, reduced or removed the

function of some body structures and organs. The human appendix that is reduced and no longer digests

rough vegetation and pelvic bones of snakes that have no legs are examples of this phenomenon.

1. The cave fish and minnow shown in Figure 3 are related, but the cave fish is blind.

a. Explain why eyesight is not an important adaptation to life in a cave. ____________________

_________________________________________________________________________

_________________________________________________________________________

_________________________________________________________________________

b. Do the appearance of the cave fish and minnow suggest common ancestry? Explain. __________

_________________________________________________________________________

_________________________________________________________________________

_________________________________________________________________________

Organs or structures that have lost their function in the organism and have become reduced in

size (because of efficiency) are called vestigial structures.

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2. Read the list of human vestigial structures shown in the table below. Suggest a possible

function for each structure and explain why it became vestigial (why that adaptation became

less important for survival). Think about organisms that are closely related to us and the

functions they have for those structures (meaning other mammals or specifically other

primates). Record your answers in the table. For the second part, analyze why this

function is no longer needed (has a different structure taken over that function? Has

the environment changed?)

Structure Possible Function(s) Why it is considered vestigial

Appendix

Muscles that make

hair stand up

Coccyx (tail bone)

Muscles that move

ears

Wisdom teeth

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